In the fabrication of fluid flow systems, whether for the purposes of conveying liquid such as petro-chemicals, or gases such as natural gas, the use of conduits or pipes is typical. As pipes can be manufactured only to a finite length, various lengths or elbows must be connected together to structure the conduit fluid conveyance means. This is accomplished by welding butt ends of pipes together or to elbows etc., or alternatively, to weld the end of a pipe to a butt flange and to juxtapose two butt flanges together by means commonly known, for example, use of bolts through each juxtaposed annular portions of each butt flange. Generally, such flanges co-operatively employ gaskets as sealing elements. The welds are tested to determine whether there is any leakage since it is mandated that the amount of fluid escaping from any weld or flange/flange interface be reduced to allowable limits.
The problem relates to creating a safe environment for performing hot work on existing pipelines carrying hydrocarbon resources. Canadian Patent No. 2,847,874 (owned by applicant) describes an isolation tool which safely isolates a line for hot work to maintain safety of personnel. The isolation tool is placed into the line upstream of where hot-work is to be performed. Once the isolation tool is properly installed and two outer seals are established, medium is brought to pressure in the annulus between the seals. Once this pressure is established, the seals are actively monitored by the technician to ensure that no harmful vapors are passing beyond the isolation tool into the hot work zone. The problem encountered by applicant with this isolation tool is that as the pipe gets bigger, the isolation tool needs to be bigger also to seal with the bigger pipe. However, this results in a heavier, more expensive tool which is difficult to install or remove. There is also a need to be able to monitor remotely rather than in close proximity to the work zone.
Accordingly, there is a need in the art for an improved isolation tool which mitigates the above problems.